Since the discovery of Norfloxacin, antibacterial activity and pharmacokinetics of quinolone antibacterial agents have been improved, and many compounds are now used in the clinical field as chemotherapeutic agents which are effective in almost systemic infectious diseases.
In recent years, increasing of bacteria having low sensitivity to quinolone antibacterial agents is becoming a problem in the field of clinics. For example, like the case of Staphylococcus aureus (MRSA) which is non-sensitive to .beta.-lactam antibiotics, a case has been increasing in which a bacterium originally resistant to drugs other than quinolone antibacterial agents becomes low-sensitive to quinolone antibacterial agents. In consequence, development of a drug having also the higher efficacy has been called for in the field of clinics.
On the other hand, it has been revealed that quinolone antibacterial agents cause a side effect in which convulsion is induced when a non-steroidal anti-inflammatory drug is simultaneously taken, as well as other side effects such as phototoxicity and the like, so that development of a quinolone antibacterial agent having the higher safety has also been called for in the field.
Quinolonecarboxylic acid derivatives having a substituent derived from 3-azabicyclo[3.1.0]hexylamine, which relates to the present invention, have been disclosed for example in JP-A-64-56673 and JP-A-7-48367 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). Although these disclose a compound represented by the following formula, they describe only about compounds having quinoline skeleton but do not describe about compounds having pyridobenzoxazine skeleton of the present invention which will be described later. ##STR2##
Also, JP-A-3-86875 and JP-A-7-149758 disclose compounds represented by the following formula, but they do not concretely disclose any compound of the present invention. ##STR3##
(In the above formula, A, R.sup.3, R.sup.6, R.sup.7, R.sup.9, R.sup.10, R.sup.25, R', W and Y are various substituents such as an alkyl group. In this connection, definition of the substituents related to the above compound is independent to that of the compound of the present invention.)
In addition, JP-A-3-86875 and JP-A-7-149758 disclose compounds represented by the following formula (A), which have pyridobenzoxazine skeleton. However, though pyridobenzoxazine derivatives having 6-amino-3-azabicyclo[3.1.0]hexan-3-yl group as a substituent at the 10-position are concretely described in these publications, there is no concrete description about pyridobenzoxazine derivatives of the present invention having 1-amino-3-azabicyclo[3.1.0]hexan-3-yl group as a substituent at the 10-position. What is more, nothing is described therein about the excellent pharmacokinetics and safety of the pyridobenzoxazine compounds of the present invention having the 1-amino-3-azabicyclo[3.1.0]hexan-3-yl group as the substituent at the 10-position. ##STR4##
(In the compounds of formula (A), definition of the substituents related to the above compound is independent to that of the compound of the present invention.)